PORTLAND — For nearly half a century, fixed base operator Northeast Air has been firmly rooted in the day-to-day life of the Portland Jetport.

“We touch nearly every plane that comes in or goes out,” Northeast Air Vice President and General Manager Mark Goodwin said last week, as he talked about the fueling and de-icing operations the company handles for commercial airlines.

By early summer, the company expects to enlarge its wingspan at 1011 Westbrook St., with a 61,000-square-foot expansion that will cost an estimated $3.5 million, Goodwin said.

“We are limited for space where the pilots can wait and where the customers can stand,” Goodwin said. “A larger and better traffic flow of customers is the biggest reason for doing it.”

The expansion and accompanying lease extension to 2056, approved by the Portland City Council on Dec. 21, was the second expansion and lease extension approved last year.

On May 4, councilors approved a 40-year lease with MAC Air Group, which is shifting much of its operations to the other side of the Jetport on land that was once a part of the Maine Youth Center in South Portland.

MAC Air will also become a fixed base operator, storing and selling fuel.

The growth at Northeast Air is specifically dedicated to customers and pilots, Goodwin said.

“We are not bringing in more airplanes, so the noise quotient is not increasing,” he said.

“The private investment being made by Northeast Air and Maine Aviation Group in the Portland International Jetport is very positive for the Jetport and all its aviation users, from small general aviation customers to our largest commercial service air carriers,” Bradbury said.

At the Dec. 21 council meeting, MAC Air Group President Allyn Caruso welcomed the lease and the competition it would bring, while noting the Northeast expansion will occur in some areas MAC will be leaving behind.

The companies had been neighbors on Westbrook Street, with MAC Air in the original airport terminal that is about 80 years old, and Northeast next door in a building completed in 1998.

Northeast Air, founded by Henry Laughlin Jr., has been at the Jetport since 1968. In addition to sales, maintenance, fueling and de-icing services, the company assists with car rentals, hotel reservations and catering.

Outside the Northeast Air offices on the runway side of the building, a curving yellow line marks the planned course of expansion. The original terminal building will soon be torn down and replaced with parking.

Goodwin said the intent is to have the new space for customers and pilots open by mid-June, when business picks up. On summer weekends, he estimated more than 400 customers may come through, largely because of families visiting children in summer camps.

Northeast Air sells and maintains aircraft and, like Caruso, Goodwin said the elimination of sales and use taxes on aircraft and aviation parts has boosted business and helped give fixed base operators some economic advantages over mid-Atlantic operators.

“Going south, it becomes very competitive and very expensive to operate,” Goodwin said. “We get a lot of people from New York and New Jersey who come for maintenance.”

While adding the Jetport is a “destination” that requires reasons for people to fly in, Goodwin said the ripple effect of the arrivals offsets the eliminated sales and use taxes.

“We are a gateway,” he said. “If we bring someone in they are more than likely to spend two or three days here. They will rent a car, stay in hotels, visit restaurants and shops. I honestly believe the economics of it offsets for the whole state actually.”

According to a memo from Bradbury to the City Council, the new lease will bring $15,200 in increased ground rent to start, with the annual rent increases tied to the urban measure of the Consumer Price Index. The city will also get monthly rent of $10 for each plane tied down at Northeast Air and increased property tax revenues from higher property valuations due to the expansion.

The expansion project has already been approved by the city Planning Board, and Goodwin expects work to begin this month, once needed building permits are in order.